AWR2243: Clarifications on POH Calculation and Use Case Assumptions

Simon, 

Please find the comments below. 

1. POH and Use Case Profiles

Your datasheets present POH values for different junction temperatures (e.g., 125°C, 95°C) with corresponding use-case percentages (e.g., 9% for 125°C).

• Are these percentages based on experimental data, market research, or industry standards (e.g., AEC-Q100 Mission Profiles)?  
• If the percentage of use-case time for a specific temperature (e.g., 125°C) were to increase (e.g., from 9% to 15%), would the POH value for that temperature change, or is it independent of the percentage?

>> They are a TI baselined profile based on what we believe are representative of typical target application mission profiles, so essentially market research. If the percentage at higher temp tiers increase, this will reduce the POH versus the published profile to achieve the same reliability level.

2. POH as an Absolute Limit vs. a Statistical Reference

From my understanding, the POH for a specific temperature (e.g., 125°C) represents the maximum reliable operation time under continuous conditions.

• Is this interpretation correct, or does the POH value include certain margins to account for statistical variations and manufacturing tolerances?
• Should the POH values in the datasheets be considered absolute limits, or are they intended as statistical references that require adaptation for specific mission profiles?

>> Correct, maximum time at that specific temp. The datasheet profile is intended as a reference, and TI engineers reliability with the profile as a whole. The profile is appropriately margined for statistical variations and tolerances. Also, TI believes the published profile should bound most typical use cases.

3. The 10,000-Hour Total POH Assumption

In some datasheets, the total POH across all temperatures approximately adds up to 10,000 hours.

• Was this an intentional design choice to align with typical automotive reliability requirements (e.g., 10 years at 1,000 hours/year)?
• How should customers interpret and apply this total value, especially for use cases that deviate from the temperature distributions provided?

>> The key point to note about 10k POH in these datasheets is the note about 50% duty cycle for RF activity, which we think is a reasonable application assumption. Generally there should be a footnote in the datasheet to that effect. If the footnote is there on a device with a 10k POH profile, that is active time for RF RX/TX, and assuming 50% RF usage, then effectively overall POH is double (e.g. 20kPOH), as generally the RF subsystem limits reliability.   

4. Recommendations for Custom Use Cases

For applications where the temperature distribution significantly differs from the datasheet assumptions (e.g., higher time spent at 125°C), what steps would you recommend for recalculating expected lifetime and reliability?

>> We would need to see the proposed profile to evaluate it.

Regards,

Aydin